Disclaimer

Supernatural is an American television series, created by Eric Kripke, produced by Kripke Enterprises, Wonderland Sound and Vision and Warner Bros. Television, distributed by Warner Bros. Television

I'm writing this for fun and I'm not making any money from this. The lines quoted from the show are in Italics.

Mesopotamia

Crowley was about 300 years old, which made him one of the younger demons rising through the ranks. And he was rising fast, only his healthy paranoia keeping him discrete. He couldn't compete with the likes of angels, old demons or knights of hell. Luckily for him, all the knights were dead, the old demons were easy to flatter and the angels could be distracted by big threats. He loved building up a the reputation of an already powerful and therefore dangerous demon, leak a few rumours about said demon's intentions to destroy humanity or attack heaven, and the angels would start following the breadcrumbs, forgetting about him.

Even more than that he carefully cultivated a non threatening facade, striking minor gentlemen's agreements with angelic counterparts, so subtle and apparently so not-evil that most of them never understood how much they were being corrupted.

Everyone so busy to do mindless violence that they never had time to watch out for a deal maker. He had a clear path to the top and he was forcing himself not to run.

He was almost completely correct in his assumption. Almost no one had had the time or clarity of mind to notice him. While most demons were facing hunters and Men of Letters, and on rare occasions angels of the Lord in their shiny, obvious armours, Crowley had attracted the attention of the intelligence division of Heaven, the only organization more paranoid than him.

One night, on the shores of the Euphrates, Crowley was celebrating quietly, having enjoyed a streak of very good deals and the imminent fall of the next demon he set up to be destroyed by Heaven.

Crowley sensed the angelic presence, and identified it almost instantly - Naomi. He had learned the name early in his demonic existence when she intervened in one of his first deals. The only reason he had remained, for the lack of a better word, alive after that encounter, was that he had backed off quickly. He was not ashamed to run away from fights he couldn't win. Naomi's power, like that of most angels, was vastly superior to his, and therefore, he was always polite with her, almost snivelling in his wish to remain uninteresting to her, and he always vanished before she could think about smiting him.

He was considering vanishing again when he sensed the chink in her grace. His host body had strong reactions even after being inhabited by the careful Crowley for a decade. And for the first time since he had known Naomi, he stayed to face her, not intending to kill her, but not ruling out the possibility.

Against his first instinct, Crowley approached cautiously the place that radiated her essence. He had his game face on, the bon vivant, the shallow, easy going, salesdemon. Under the cold starlight, he looked at the nun that contained Naomi's spirit. Barely contained it. He noticed the pain, the metaphorical cracks in the armour. He had to take advantage, or at least study an angel on the brink of falling apart.

"Good evening," he said in his most sensual, yet non threatening tone.

The angel looked up at him, and her sparkling blue eyes should have been a warning. Even lacking the angelic tell-tale sign of imminent smiting her look was fierce.

"Easy there, luv. Not gonna bite ya," he whispered.

The woman took a deep breath, obviously trying to control the pain. His heightened sense of sight allowed him to notice the blue veins showing unnaturally on her skin. His mind tried to find the right epithet milk white or marble white? What was she, a mother figure, a loving, innocent angel? Or was she one of those angels with the moral rigidity of a marble statue? Didn't matter all that much. What mattered most was that she was vulnerable. And he was a still young demon. Taking down an angel would be a lovely, lovely trophy.